A communication system includes a media of limited capacity connecting a source of information (data) to a plurality of users. The media could be either a wired media or a wireless media. In order to enable all users to share the limited capacity media, the communication system often enforces one or more Quality of Service (QoS) policies. One QoS policy, which is commonly used in communication systems, is maximum information rate (MIR).
A communication system serving a plurality of users often enforces MIR on more than one level. In such system, MIR has to be enforced both on a per user basis, but also the total information rate must be enforced, often in accordance with the limited capacity of the media. However, when MIR is enforced on more than one level, independently limiting the transmission information rate at each level often results in undesired outcomes.
Enforcing MIR of the media without considering how the limited capacity is being distributed between the multiple users often results in lack of fairness between the users. For example, if the MIR value associated with one user is twice the MIR value associated with a second user, independent enforcement of the media MIR often results in reducing the information rate for both users but without the capacity allocated to the first user being twice as high as the capacity allocated to the second user.
On the other hand, since the media is there, it is desirable to utilize as much of its available capacity as possible as per the existing demand from all users. If the media capacity is distributed between the users only in accordance with MIR values associated with the users, when demand of some users is less than their associated MIR values while demand of other users exceeds their associated MIR, the media might be underutilized while information that could be transmitted over the media is not transmitted. Instead, it would be desirable to allocate each user more than its MIR and to maximize the utilization of the available capacity. Yet, the available capacity has to be distributed between the users on a fair basis, e.g. a user which has higher MIR has to get higher capacity.